Improvement in suction apparatus for paper-machines



UNITED STATES PATENT OEEICE.

WILLIAM MCLAUGHLIN, OF LEE, MASSACHUSETTS.

IMPROVEMENT IN SUCTlON APPARATUS FOR PAPER-MACHINES.l

Specification forming part of Letters Patent No. 138,173, dated April`22, 1873; application filed l February 12, 1873.

T0 all whom it may concern:

Beit known that I, WILLIAM MGLAUGHLIN, of Lee, in the county ofBerkshire and State of Massachusetts, have invented a new and ImprovedSuction Apparatus for Paper-Makling Machines; and I do hereby declarethe Figure l represents a plan or top View ofV my invention. Fig. 2 is atransverse vertical section of the same.

Similar letters indicate corresponding parts.

This invention consists in the arrangement of rollers in the suction-boxof a paper-making machine, said rollers being made to revolve with theweb carrying the sheet of paper, while the suction is taken between therollers in such a manner that the web on moving over the suction-box issupported by said rollers, and as the rollers revolve with a super-Iicial velocity equal to the speed of the web, the motion of the web, asthe same is depressed by the suction, is not materially impeded, and thepartswhich support the web during its passage over the suction-box arenot liable to wear out. Each ofthe web-supporting rollers moves in a boxprovided with packing, which can be pressed up against the circumferenceof its roller in such a manner that no air is allowed to pass into thesuction-box on the sides of the rollers, and consequently the efect ofthe suction is not disturbed.

In the drawing, the letter A designates the suction-box of apaper-making machine, said suction-box being secured to the frame of thepaper-making machine in the usual position, so that the web B, Fig. 2,passes over the same, and that the sheet of paper resting on said web isexposed to the suction during its passage over the suction-box. In thesuctionbox I place two rollers, C' C, which revolve with a superficialVelocity equal to the speed of the web, and in the same direction inwhich the web moves, and which are so situated that by means of theseset-screws and of the follower the packing can be pressed up against thesurface of its roller with more or less power, and by these means theescape of air on the sides of the roller is prevented, and the effect ofthe suction is not disturbed. The suction takes place through auaperture, H, in the bottom of the suction-box between the two rollers CG, and the suction-box is adjusted to the width of the sheet of paperresting on the web by movable partitions I, such as are generally usedin suction-boxes of papermaking machines, with that exception, however,that my movable partitions are adapted to the form of the rollers C (l.

In suction-boxes of the usual construction a perforated plate of sheetmetal is secured on the top of the suction-box to support the web duringits passage over the same, and as the suction draws the web down saidweb is depressed with great force on the perforated top plate of thesuction-box, and thereby the motion of the web is impeded, and theperforated top plate is caused to wear out in a short time, while theweb itself also wears.

By my moving supportin g-rollers the motion of the web is not impeded;and, furthermore, the rollers are not liable to wear, so that aconsiderable saving is effected by my invention.

If desired, three or more supporting-rollers might be used instead oftwo, as above described.

What I claim as new, and desire to secure

